Wire rope has been used for a variety of applications. The applications are so numerous and operating conditions so variable that no one type of wire rope can be universally applied. This invention relates primarily to wire rope which is subjected to the operating conditions found during earth excavation. Excavator wire rope must possess a high degree of abrasion resistance, bending fatigue resistance, strength and ductility. In addition, it is economically desirable that the service life of excavator wire rope be as long as possible.
It has been found that when the king wire, i.e. the center wire of a strand, breaks, the shape and integrity of the strand is immediately affected by the shifting or movement of the layers of wires being supported by the king wire. Such movement of wires results in a loss of breaking strength of excavator wire rope.
It has also been found that the physical properties of the wires in the outer layer of each wire strand of a wire rope have a significant influence on the performance and service life of excavator wire rope. Such wires should have a high degree of resistance to abrasion and bending fatigue.